Short forms of two condition-specific quality-of-life questionnaires for women with pelvic floor disorders (PFDI-20 and PFIQ-7)

Objective

To develop short forms of 2 valid and reliable condition-specific quality-of-life questionnaires for women with disorders of the pelvic floor including urinary incontinence, pelvic organ prolapse, and fecal incontinence (Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire).

Study design

Data from the 100 women who contributed to the development and validation of the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire long forms were used to develop the short-form questionnaires. All subsets regression analysis was used to find the items in each scale that best predicted the scale score on the respective long form. When different items appeared equivalent, a choice was made on item content. After development, the short forms and the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire long forms were administered preoperatively to 45 women with pelvic floor disorders scheduled to undergo surgery to evaluate the correlation between short and long forms in a second independent population. The short forms were readministered 3 to 6 months postoperatively to assess the responsiveness of the instruments.

Results

The short-form version of the Pelvic Floor Distress Inventory has a total of 20 questions and 3 scales (Urinary Distress Inventory, Pelvic Organ Prolapse Distress Inventory, and Colorectal-Anal Distress Inventory). Each short-form scale demonstrates significant correlation with their long-form scales (r=.86, r=.92, and r=.93, respectively, P < .0001). For the Pelvic Floor Impact Questionnaire short form, the previously developed short form for the Incontinence Impact Questionnaire-7 was used as a template. The 7 items identified in the previously developed Incontinence Impact Questionnaire-7 short form correlate highly with the Incontinence Impact Questionnaire long form (r=.96, P < .0001) as well as the long forms of the Colorectal-Anal Impact Questionnaire scale (r=.96, P < .0001) and the Pelvic Organ Prolapse Impact Questionnaire (r=.94, P < .0001). All subsets regression analysis did not identify any items or combination of items that correlated substantially better for any of the 3 scales. The scales of the Pelvic Floor Distress Inventory-20 and Pelvic Floor Impact Questionnaire-7 maintained their excellent correlation to the Pelvic Floor Distress Inventory and Pelvic Floor Impact Questionnaire long forms in the second independent sample (r=.88 to .94 for scales of Pelvic Floor Distress Inventory-20; r=.95 to .96 for scales of Pelvic Floor Impact Questionnaire-7, P < .0001 for all). The test-retest reliability of each scale was good to excellent (intraclass correlation coefficient 0.70 to 0.93, P < .001 for all scales). The scales and summary scores of the Pelvic Floor Distress Inventory-20 and Pelvic Floor Impact Questionnaire-7 demonstrated moderate to excellent responsiveness 3 to 6 months after surgery.

Conclusion

The Pelvic Floor Distress Inventory-20 and Pelvic Floor Impact Questionnaire-7 are valid, reliable, and responsive short forms of 2 condition-specific quality-of-life questionnaires for women with pelvic floor disorders.

Key words: Quality of life, Urinary incontinence, Fecal incontinence, Pelvic organ prolapse, Pelvic floor